This invention relates to a mobile apparatus for cleaning bar-mounted remnants of carbon blocks, particularly anode blocks.
As is well known, the used-up carbon anodes (anode remnants as they are called) that occur in, for example, the electrolytic extraction of aluminium, become coated with relatively thick incrustations consisting of a mixture of aluminium oxide and solidified material from the melt. For reasons of economy, it is necessary to remove these incrustations from the anode remnants, so that they may be recyled for use in the electrolysis process, and so that the anode remnants can be used for producing new carbon anodes. In practice, the cleaning of the anode remnants is still mainly carried out manually by using tools such as air lances.
It is also known to carry out the cleaning of anode remnants by mechanical means. (See DE-OS Nos. 3 242 285, 3 032 525 and DE-PS No. 3 227 441). In this case, use is made of a carriage having a pallet (or a crane trolley) for conveying the bar-mounted anode remnants to a stationary cleaning installation which is provided with a breaking tool for separating the incrustations from the remnants. Unfortunately, during transport, some of the adhering melt is lost, and this leads to re-cycling losses, and also to environmental pollution, since fluorine gas is emitted during cooling.
A mobile anode-block cleaning apparatus is known (see U.S. Pat. No. 4,119,505) which consists of a lifting device and a breaking tool. The lifting device is arranged on a crane trolley, and is used for lifting anode blocks out of an electrolytic bath. The breaking tool is then used to remove the incrustations adhering to the anode remnants, while the remnants are positioned above the melt bath. In this way, the broken-off incrustations are returned directly to the melt bath. The apparatus is controlled from a driving cabin, so that the operator is protected from the heat and dust given off by the remnants. Unfortuantely, the use of this apparatus results in substantial environmental pollution.
The aim of the invention is to provide a mobile anode-block cleaning apparatus which can reliably separate anode block remnant incrustations in the vicinity of an electrolytic smelting plant, without excessive environmental pollution.